Skip to main content

All Questions

1 vote
2 answers
96 views

why is $L=\{\{x\mid x<q(i)\}\mid i\in\mathbb{N}\}$ not the set of all Dedekind cuts?

Let the set $L$ be definded as $$L=\{\{x\mid x<q(i)\}\mid i\in\mathbb{N}\},$$ where $q(i)$ is some bijection from $\mathbb{N}$ to $\mathbb{Q}$. Clearly, every member of $L$ is neither an empty set ...
Mohamed Mostafa's user avatar
0 votes
0 answers
31 views

Set representation of (real) numbers [duplicate]

Using the Von Neumann representation we can represent the non-negative whole numbers using the empty set, e.g. $1$ as {$\emptyset$}. How do we represent with this notation numbers like $\sqrt2, -1, \...
user8363722's user avatar